1. Field of the Invention
This invention relates to methods for making pallets, and more particularly, to a method and apparatus for boring and bolting pallets.
2. Related Art
Wooden pallets for transporting and storing goods are widely used in commerce and industry. Due to heavy loads and rough handling, pallets are frequently destroyed or damaged and generally have a relatively short useful life. Therefore, a continuous supply of substantial quantities of new replacement pallets is needed in industries which involve bulk storage and handling operations.
Conventional pallets have a plurality of wooden components that are nailed or bolted together. Such conventional bolted pallet construction processes require each component of a pallet to be drilled separately, then the pallet is assembled using bolts at a later date. Problems arise with the assembly in that the holes in joining components may or may not align properly. If mis-aligned, the edges of the components of the resulting pallet will not be flush. Moreover, even if one could drill the holes in exactly the right location it would be very time consuming to line up all of the parts and holes so as to bolt the parts together with proper alignment.
Therefore, there is a need for an apparatus and process in which a wooden pallet is drilled quickly and efficiently such that when bolted together, all joining components of the pallet are aligned properly resulting in flush edges.
In addition, conventional bolted pallets use step drills for drilling the bores in the pallet. Step drills are known in the prior art and are commercially available; however, such step drills only have two diameters. Therefore, the resulting bore from a conventional step drill does not provide a means for making the head of a bolt recessed within, or flush with, a panel top component. By only providing a bore with two diameters, the head of a bolt must rest on the top surface of a panel top component. Therefore, when moving a pallet, the head of the bolt will catch on objects and make it difficult to slide or move a pallet in and out of different positions.
Therefore, there is a need for an apparatus and process in which the bores of a pallet are drilled having three diameters, thereby allowing the head of a bolt to be recessed in, or flush with, the top surface of a panel top component of the pallet.
The present invention solves the problems encountered with previous efforts at manufacturing bolted pallets by providing a method and apparatus that can quickly position pallet components in an assembly jig, drill bores through joining components simultaneously, and keep the components in place while the pallet is bolted together.
The apparatus for boring and bolting pallets includes a means for loading an assembly jig with two or more main components, two or more cross components, a plurality of spacer support components, and a panel top component (collectively, components). The assembly jig holds the main components, cross components, spacer support components, and panel top component in proper position to form an incomplete pallet. The apparatus also includes a means for simultaneously boring each intersection of a main component, spacer support component, cross component, and panel top component of the incomplete pallet while the incomplete pallet is being contained in the assembly jig. The boring of the components is accomplished by raising a plurality of drills from below the incomplete pallet. After drilling the bores from below, the assembly jig contains a bored pallet wherein all of the needed bores have been drilled concurrently. The apparatus also includes a means for delivering the assembly jig containing the bored pallet to a bolting table where the main components are bolted to the cross components, the spacer support components, and the panel top component, resulting in a bolted pallet or pallet. Once the pallet is removed from the assembly jig, the apparatus can include a means for returning the assembly jig to the means for loading in order to receive new components for a new pallet.
The method for boring and bolting pallets includes filling an assembly jig located at a pre-boring station with two or more main components, two or more cross components, a plurality of spacer support components, and a panel top component to form an incomplete pallet; simultaneously boring the intersections of the main components, the cross components, the spacer support components, and the panel top component of the incomplete pallet, resulting in a bored pallet form; delivering the assembly jig containing the bored pallet form to a bolting table; and bolting all of the components together to create a pallet. The method can also include means for removing the pallet from the assembly jig, and a means for returning the assembly jig to the pre-boring station in order to receive new components for a new pallet.
The present invention uses a drill bit having three different diameters, resulting in a bore having corresponding three different diameters. This provides the means for the head of the bolts to be recessed in, or flush with, the exterior surface of the pallet. The advantage of recessed bolts is that the pallet can be easily slid into position without the bolt heads catching on anything and interfering with the moving of the pallet.
As a result of the boring and bolting process, a pallet is produced that has two or more main components, two or more cross components, and a panel top component, thereby creating four or more intersections of the main components, the cross components, and spacer support components. The pallet has a bore centrally located at each of the main component/cross/spacer support component intersections with a bolt inserted through each bore. Each bolt is secured with a pallet nut such that the head of the bolt and the pallet nut are countersunk below the exterior surface of the pallet.
An advantage of the present invention is that the external edges of the pallet are flushxe2x80x94meaning that the panel top component, cross components, spacer support components, and main components are flush with one another such that no one component protrudes beyond any of the others. This can be done without grossly over-sizing the bores which makes the joints of the pallet loose and weak.
A second advantage of the present invention is that all bores of a pallet are drilled simultaneously and with precision resulting in a pallet being assembled quickly and efficiently because all components are automatically aligned. In operation, it has been shown that the present invention results in more pallets being made in fewer man hours, thereby reducing the labor cost of pallet construction.